1. Technical Field
The present invention relates to an image processing apparatus, an image forming apparatus, an image processing method, and a recording medium recording a computer program for performing a process for superimposing pixel data of a plurality of color components.
2. Description of Related Art
In order to prevent degradation of image quality of an image formed on a paper medium by an image forming apparatus such as a copier or a printer, a trapping process and a smoothing process are proposed. A process for superimposing pixel data of a plurality of color components on each other (hereinafter referred to as a trapping process) is a process for preventing white gaps from appearing when a misregistration occurs and a page background has been exposed. The smoothing process is a process for improving resolution while reducing a jaggy (stair-stepping edges appearing in curved or sloping lines of text or an image).
When an image forming apparatus performs image formation at high resolution based on low-resolution input image data, it is necessary to perform the trapping process with respect to the image data which is converted to high-resolution image data in order to prevent degradation of image quality. As a result, since the image forming apparatus needs a memory for storing the image data which is converted to the high-resolution image data, the problem occurs that a circuit scale is increased.
Consequently, an invention capable of performing the trapping process while controlling an increase in the circuit scale without causing a reduction in a processing speed has been proposed (for example, Japanese Patent Application Laid Open No. 2004-223850). In such an image forming apparatus, a buffer for the trapping process is shared with a buffer for input image data, thereby preventing an increase in the circuit scale, and preventing a reduction in the processing speed by performing the trapping process after conversion to bitmap data.